1. Field of the Invention
The present invention relates generally to a lens, and more particularly to a miniature image pickup lens.
2. Description of the Related Art
With advancement in technology, image devices, such as camera, video camera, microscope, and scanner, are made smaller and lighter for portability and operation that the lenses incorporated in such image devices have to reduce its size. Except that, the lenses must have high optical performance, such as high zoom ratio, high resolution, and high contrast. Consequently, small size and high optical performance are the important facts of modern lenses.
In order to raise the optical performance, more and more lens groups are provided in the zoom lens. As we know, some zoom lenses even have ten lens groups or more. It is obvious that more lens groups will cause the lens bigger and heavier. However, when the lens has fewer lens groups, it may have a small size, but the optical performance is poor.